Comparison

Cuckoo Clock Calibration vs Twelve O'clock

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Cuckoo Clock Calibration

This app transforms your iPhone into a highly accurate sensor for calibrating cuckoo and pendulum clocks. It measures clock beats, calculates daily gain or loss, and guides you through precise adjustments for optimal timekeeping.

Highlights
  • Precise clock beat period measurement
  • Daily gain/loss calculation
  • Train count sensor with 1μs accuracy
  • Adjustable signal gain and detection threshold
  • Reference timing table with user-defined clocks
  • Waveform display for tick readings
Features
Currently charting
Read full description

The best and most accurate app for Cuckoo and Pendulum clocks calibration. Easily measure your Clock beats period and adjust it to a known correct value. Turn your iPhone into a precise train count sensor with an unbelievable 0.001 milliseconds (1μs) accuracy!! Get a quick and precise drift reading of how many seconds/minutes your clock is going to gain or loose per day. Every Cuckoo Clock owner knows that a mechanical clocks are not as accurate as modern day quartz clocks. This is because the clock mechanism is influenced by temperature, humidity, barometric pressure, breeze and others environmental conditions and therefore requires frequent adjustment. When you are regulating the pendulum of your Cuckoo Clock today, you are attempting to achieve the best timekeeping possible by a trail and error method by lifting the pendulum bob up or down and hope for a better accuracy. Using this app you can finally get a reading of your Clock ticks timing and precisely calibrate it to a known value. How to calibrate your Clock using this app: 1. Run this App and measure your Clock timings using the iPhone microphone 2. Use the Signal Gain and the Detection Threshold sliders to adjust the measured signal 3. Select a reference timing for calibration from the clock reference table or set your own reference timing 4. Read the accuracy level of your clock vs. the reference timing 5. Adjust your Clock pendulum bob to get the best accuracy! 6. Review how many seconds/minutes your Clock will gain or lose per day based on your current calibration The app will presents your Clock beats period reading as well as BPH (beats per hour) and BPM (beats per minutes) values. An accurate waveform display of the microphone signal will help you to adjust the tick readings for the best measurement. Animated Indicators will guide you through the calibration process. Manage the app Reference Timings table and add user defined clocks in addition to the predefined ones to support all your clocks. This app will turn your iPhone into a powerful measurement tool which normally costs hundreds of dollars.

About

Twelve O'clock

Easily track the accuracy of your mechanical watches over time. Manually log checkpoints to calculate seconds per day and visualize performance with charts. Manage your watch collection with photos and learn more about horology.

Highlights
  • Manage watch collection
  • Add/edit/remove watches
  • Include watch photos
  • Track watch accuracy
  • Calculate seconds per day
  • View accuracy charts
  • Horology content
Features
Read full description

Twelve O’clock is an app that helps track your watch accuracy easily in a realistic way. I can’t stress this enough: it’s “tracking”, not measuring instantaneous accuracy like a timegrapher device. It’s a manual and oldschool job but it brings so much fun. It reminds me of the old days when I had to synchronize my watch to the clock on the TV at 7pm every day. With Twelve O'clock you can: ** MANAGE YOUR WATCH COLLECTION * Add, edit, remove any item in a list of your watch collection * Include a nice wristshot of each watch ** KNOW YOUR WATCH ACCURACY * Simply add some checkpoints and let the app calculate the accuracy in *second per day* * A nice chart of the accuracy over the time ** LEARN MORE ABOUT HOROLOGY * Curated content for watch lovers (like me)

Screenshots

Cuckoo Clock Calibration4 screens
Twelve O'clock4 screens

Verdict

The call

The clearest difference is price: Twelve O'clock at Free against Cuckoo Clock Calibration's $0.99. Cuckoo Clock Calibration's advantage is rating (4.9 vs 4.4) and in-app purchases (none vs 1). On review sentiment, ratings volume, update cadence and ads there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Twelve O'clock is free to download; Cuckoo Clock Calibration costs $0.99 up front. Twelve O'clock sells 1 one-off in-app purchase. Cuckoo Clock Calibration asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Cuckoo Clock Calibration holds the better App Store score, 4.9 against 4.4. Both are backed by a comparable volume of ratings — 36 and 83 respectively. Written reviews complicate that: 86% of Cuckoo Clock Calibration's written reviews are positive against 91% of Twelve O'clock's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Cuckoo Clock Calibration ships an update monthly, Twelve O'clock every 3 weeks. The most recent releases landed on October 26, 2026 and October 24, 2026 respectively.

Scorecard6 real differences · 5 level
Cuckoo Clock Calibration versus Twelve O'clock: the parameters behind the verdict, then further details
ParameterCuckoo Clock CalibrationTwelve O'clock
Price$0.99Free — better
Rating4.9 (36 ratings) — better4.4 (83 ratings)
Positive reviews85.5% of reviews91.1% of reviews — better
Number of ratings3683 — better
Update frequencyMonthlyEvery 3 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
Best chart rank#161 — better—
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS9.0 — better15.0
Further details — not scored
Size19 MB46 MB
Age rating4+4+
DeveloperNir HamzaniHieu Pham

Customer experience

Cuckoo Clock Calibration

All ratings36 ratings
Positive97.2%
Neutral2.8%
Negative0.0%
Written reviews69 reviews
Positive85.5%
Neutral2.9%
Negative11.6%

Twelve O'clock

All ratings82 ratings
Positive84.1%
Neutral1.2%
Negative14.6%
Written reviews123 reviews
Positive91.1%
Neutral0.8%
Negative8.1%

User reviews

Cuckoo Clock Calibration

From 36 App Store ratings

What we love

  • 👍 Easy to use
  • 💰 Affordable price
  • ✅ Accurate readings
  • ⏱️ Saves time
  • 🛠️ Helps with clock repair

Room to improve

  • ❓ Confusing directions
  • 📉 Inconsistent readings sometimes
  • 🚫 External microphone issues
  • 🎛️ Limited reference clocks
  • 🗣️ Name not universal

Twelve O'clock

From 83 App Store ratings

What we love

  • 👍 Intuitive and simple user interface
  • 💰 Excellent value at $0.99 one-time purchase
  • 🎯 Accurate watch accuracy tracking
  • ⏱️ Flexible checkpoint timing (0, 15, 30, 45 seconds)
  • 📊 Clear data visualization and graphs

Room to improve

  • 🐛 App freezes and crashes frequently
  • 💾 Data loss after updates
  • ⚠️ Free version severely limited (5 checkpoints only)
  • 🔔 Silent mode prevents beeping sounds
  • 🎯 Requires learning curve for some users

Bugs and requests

Cuckoo Clock Calibration

Reported bugs

7 issues
  • App closes after setting reference
  • App crashes on startup after reference beat memory use
  • App crashes
  • App crashes and requires reinstallation
  • App crashes on iPhone 6s
Show 2 more
  • App crashes on iPhone 7+
  • App crashes on iPhone 6s (v 12.4.1)

Requested features

20 requests
  • Accurate beat frequency display
  • Level indicator display
  • External microphone support
  • Plot period over time
  • Allow reference periods over 1 second
Show 15 more
  • Save measurement data
  • Allow frequency of 60.000 BPM
  • Repackage/rename for all mechanical clocks
  • Add Russian language
  • Add parameters for specific Swiss and Soviet clocks
  • Add lower beats per minute (e.g., 8 BPM)
  • Add a distribution chart for beats
  • Add seconds lost/gained per day display
  • Broader clock options/community sharing of references
  • More user-input references
  • Better graph or display for out of beat
  • Allow input reference beat rate directly by digits
  • Add a feature to help get the clock in beat (e.g., which way to bend crutch)
  • Invert display option
  • Explanation of calculations for drift and instantaneous beat

Twelve O'clock

Reported bugs

11 issues
  • App freezes at loading requiring phone restart
  • Data deletion after app updates
  • Data loss on app crash
  • Graph display glitches after checkpoints
  • Photo checkpoint feature returns 'old photo not supported' error
Show 6 more
  • Beeping only works when phone not in silent mode
  • Sort function not working
  • Screenshot sharing produces blank page
  • Calculation errors showing ~150 second variance
  • Checkpoint history doesn't display correctly
  • Swiping left to delete checkpoints not intuitive

Requested features

18 requests
  • iCloud/cloud synchronization across devices
  • Notifications or reminders for checkpoints
  • Current time button on checkpoint screen
  • Larger buttons for 15/30/45 second marks
  • Power reserve tracking
Show 13 more
  • Wear frequency tracking
  • Average accuracy by watch position
  • Widget support
  • Atomic clock built into app
  • Regulator clock layout for time setting
  • In-app feedback option (instead of Twitter)
  • Automatic time reading from watch photos
  • 12-hour time format option
  • Sort function improvements
  • Year display in checkpoint history
  • Chrono24 account integration
  • Regular article updates
  • Export to Excel/CSV

In-app purchases

None

Cuckoo Clock Calibration

No in-app purchases

1 purchases

Twelve O'clock

One-time1
  • Twelve Plus$1.99

Questions

Is Cuckoo Clock Calibration free?
Cuckoo Clock Calibration costs $0.99, with no in-app purchases.
Is Twelve O'clock free?
Twelve O'clock is free to download, with in-app purchases available.
Which has better reviews, Cuckoo Clock Calibration or Twelve O'clock?
Cuckoo Clock Calibration is rated higher. Cuckoo Clock Calibration averages 4.9 out of 5 from 36 ratings, while Twelve O'clock averages 4.4 from 83 ratings.
Do Cuckoo Clock Calibration or Twelve O'clock have ads?
Neither Cuckoo Clock Calibration nor Twelve O'clock shows ads.
Which is updated more often, Cuckoo Clock Calibration or Twelve O'clock?
Cuckoo Clock Calibration ships an update monthly, and Twelve O'clock every 3 weeks. Most recently, Cuckoo Clock Calibration was updated on October 26, 2026 and Twelve O'clock on October 24, 2026.

Other comparisons